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        function Obj() {
            function fn() {
                console.log(this);
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            Obj.prototype.fn = fn;
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        // new Obj().fn();

        class Obj2 {
            say() {
                console.log(this);
            }
            work = () => console.log(this)
        }
        // let {say} = new Obj2();
        // say();
         let {work} = new Obj2();
        // work();
        let b = {
            a:()=>console.log(this),
            say(){
                let a = (function a () {
                    console.log(this);
                }).bind(this);
                return a;
            }
        }
      let a =  b.say()();
    //   a();
       
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